A U.S. Department of Energy initiative aimed at speeding electric grid buildout should focus on establishing more ties between the nation's Western and Eastern Interconnections, a panel of experts said Jan. 28.
The DOE launched the program, dubbed the Building a Better Grid initiative, earlier in January following the enactment of a bipartisan infrastructure bill that contained billions of dollars for grid infrastructure and expanded federal siting authorities.
As part of the initiative, the DOE will conduct a study to identify high-priority national transmission solutions capable of relieving congestion and accommodating more clean energy resources.
More ties needed linking interconnections
One of the biggest limitations with the current U.S. grid is a lack of east-west transmission lines, panelists asserted during a Jan. 28 event hosted by the U.S. Energy Association.
"Right now, the reason we have a duck curve in California is that California runs north to south and the sun sets on California all at once," Highley said.
Transmission infrastructure in the wind- and solar-rich Midcontinent ISO and Southwest Power Pool Inc. regions, the nation's two largest regional grid operators in terms of geography, also mostly runs north to south, Highley noted.
"To get a federal entity that could study and bring together private companies to help build and construct this network that brings solar east to west is going to resolve a lot of our issues with integrating renewables onto the grid," Highley said.
SPP Executive Vice President and COO Lanny Nickell used a swimming pool analogy to describe transmission bottlenecks choking off potential exports of renewable energy generation.
According to a DOE grid study, only seven high-voltage direct-current lines linked the U.S. Eastern and Western Interconnections as of October 2020. The lines offer just 1,320 MW of transfer capacity, while 700,000 MW of generating capacity exists in the Eastern Interconnection and 250,000 MW exist in the Western Interconnection.
"Having two swimming pools and having the need to transfer water from one swimming pool to another and those swimming pools are linked by a common garden hose — that's what we've got today," Nickell said.
Nickell suggested that the value of east-west transmission ties was on clear display in February 2021 during the Texas arctic blast. SPP imported up to 14% of the region's electricity needs from the east, while the grid operated by the Electric Reliability Council of Texas Inc., which is largely siloed from the rest of the U.S., was limited to just 1.5%, Nickell noted.
DOE as an anchor tenant
Elliot Mainzer, president and CEO of the California ISO, argued that the DOE initiative should also bring more focus to the commercial subscription of transmission lines.
Under the bipartisan infrastructure legislation, the DOE is authorized to serve as an anchor customer on new and upgraded transmission lines to help facilitate private financing and construction. The department is specifically authorized to buy up to 50% of a line's planned capacity for a term of up to 40 years and then market that capacity to private companies.
"Generally, when you can actually line up the beneficiaries and the buyers and you can get transmission subscribed, things start to move a little bit more effectively," Mainzer said.
Nickell added that SPP has seen failures in the transition from planning to construction when project opponents can successfully demonstrate a clear lack of benefits.
"When a particular transmission line or asset is being routed through a state, that state needs to see a benefit," Nickell said. "When they don't see it or don't believe it, that's when it becomes practically impossible to see that project through to construction."